JP5047050B2 - Titanium-containing aqueous solution and method for producing the same - Google Patents

Description

  The present invention relates to a titanium-containing aqueous solution, a method for producing the same, a method for producing a titanium-supported refractory inorganic oxide carrier, and a hydrotreating catalyst for hydrocarbon oil. Specifically, the present invention relates to a titanium-containing aqueous solution suitable for uniformly supporting titanium on a refractory inorganic oxide carrier, a method for producing the titanium easily and inexpensively, and using the titanium-containing aqueous solution, a high dispersion The present invention relates to a method for producing a refractory inorganic oxide support having titanium supported thereon, and a high-activity and low-cost hydrocarbon oil hydrotreating catalyst in which an active metal is supported on this support.

Conventionally, it has been known that titanium oxide exhibits specific activities for various reactions as a catalyst itself or an active metal carrier. However, since titanium oxide alone has poor moldability and a small specific surface area, it is often studied that a titanium oxide is supported on a molded body of a refractory oxide rather than using titanium oxide alone as a carrier. .
As a method of supporting titanium oxide on a refractory oxide molded body (support) such as alumina, the solution is adjusted to an amount that the support absorbs water, and a pore filling method in which the support is impregnated, or a large excess solution. There is a method of immersing the carrier.

As the titanium-containing solution, an aqueous solution containing only titanium (ion) as a metal and an organic titanium compound solution dissolved in an organic solvent are used. Since an aqueous solution containing titanium tends to be specifically hydrolyzed, strong acidic solutions such as titanium tetrachloride and titanium sulfate are known. On the other hand, alkoxide compounds and acetylacetonate compounds are known as organic titanium compounds. However, these compounds have the following disadvantages.
In addition to being strongly acidic and difficult to handle, aqueous solutions of titanium tetrachloride and titanium sulfate need to be supported in a very low pH range of pH 1 or lower because they are easily hydrolyzed. However, even in the case of such an aqueous solution containing titanium such as titanium tetrachloride having a pH of 1 or less, when it comes into contact with the refractory oxide, a hydrolysis reaction occurs rapidly, and titanium is not easily supported on the refractory oxide. Therefore, the effect of titanium may not be exhibited remarkably. In addition, chlorine ions and sulfate ions may adversely affect the catalytic activity, and further, chlorine ions cause corrosion for industrial equipment, so it is preferable that none of them be included.

  On the other hand, organic titanium compounds (such as alkoxide compounds and acetylacetonate compounds) are preferable to titanium tetrachloride and titanium sulfate because they do not contain chloride ions or sulfate ions, but have the disadvantage of being easily hydrolyzed even with a small amount of moisture. When the organic solvent solution is impregnated or immersed, it comes into contact with trace amounts of moisture contained in the refractory oxide, so that titanium hydroxide precipitates, so that titanium is unevenly distributed outside the refractory oxide compact. Furthermore, such an organic titanium compound is expensive, and it is extremely difficult to economically apply it to a hydroprocessing catalyst for a hydrocarbon oil that is required in large quantities.

  Under such circumstances, the present invention uses a titanium-containing aqueous solution suitable for uniformly supporting titanium on a refractory inorganic oxide carrier, a method for producing the same easily and inexpensively, and using the titanium-containing aqueous solution. An object of the present invention is to provide a method for producing a refractory inorganic oxide support having titanium dispersed in a highly dispersed state, and a high-activity and low-cost hydrocarbon oil hydrotreating catalyst in which an active metal is supported on this support. To do.

As a result of intensive studies to achieve the above object, the present inventors have dissolved titanium materials such as titanium hydroxide, titanium hydrated oxide, and titanium metal in water under specific conditions, Can be easily and inexpensively obtained by stabilizing titanium with a certain compound so that it can be dissolved in water well, is stable at a wide pH, and has a significantly reduced amount of impurities such as sulfate ions and chloride ions. I found.
In addition, by bringing the titanium-containing aqueous solution into contact with a refractory inorganic oxide support, a refractory inorganic oxide support supporting titanium in a highly dispersed state can be easily obtained, and a specific metal is further supported on the refractory inorganic oxide support. It has been found that a hydroactive catalyst for hydrocarbon oil with high activity and low cost can be obtained.
The present invention has been completed based on such findings.

That is, the present invention
(1) It contains titanium hydroxide and / or titanium hydroxide, ammonia, hydrogen peroxide, and hydroxycarboxylic acid, and the molar extinction coefficient ratio of wavelengths 400 nm and 440 nm to wavelength 360 nm ε = (ε _{400 nm} + ε _{440 nm} ) / ε _{360 nm} ( _Wherein ε ₃₆₀ nm represents a molar extinction coefficient at a wavelength of 360 nm, ε ₄₀₀ nm represents a molar extinction coefficient at a wavelength of 400 nm, and ε ₄₄₀ nm represents a molar extinction coefficient at a wavelength of 440 nm). Aqueous solution.
(2) A method for producing a titanium-containing aqueous solution according to the above (1), wherein ammonia and hydrogen peroxide are added to the titanium raw material to dissolve titanium, and then hydroxycarboxylic acid is added.
(3) The method for producing a titanium-containing aqueous solution according to the above (2), wherein the titanium raw material is at least one selected from titanium hydroxide or titanium hydroxide.
(4) In the presence of ammonia and hydrogen peroxide, titanium hydroxide and / or titanium hydroxide is dissolved in water in the range of pH 7.0 to 14.0, and titanium ions are stabilized with hydroxycarboxylic acid. The method for producing a titanium-containing aqueous solution according to (1), which is substantially free of chlorine ions or sulfate ions,
(5) The titanium-containing aqueous solution described in (1) above or the titanium-containing aqueous solution obtained by the method described in any of (2) to (4) is contacted with a refractory inorganic oxide support. And (6) the titanium-supported refractory inorganic oxide support obtained by the method described in (5) above, and the groups 6 and 8 of the periodic table. A hydrotreating catalyst for hydrocarbon oils carrying at least one metal selected from metals belonging to Group 9 and Group 10,
Is to provide.

(1) Titanium-containing aqueous solution The titanium-containing aqueous solution according to the present invention contains titanium hydroxide and / or titanium hydroxide, ammonia, hydrogen peroxide, and hydroxycarboxylic acid, and has molar absorption at wavelengths of 400 nm and 440 nm with respect to a wavelength of 360 nm. The coefficient ratio ε is 0.05 or more. When the molar extinction coefficient ratio ε is less than 0.05, the complexation of titanium ions is insufficient, and the stability of the titanium-containing aqueous solution is lowered. The molar extinction coefficient ratio ε is particularly preferably 0.07 or more.
The molar extinction coefficient ratio ε is expressed by the following equation: ε = (ε _{400 nm} + ε _{440 nm} ) / ε _{360 nm}
(Where ε _{360 nm} is the molar extinction coefficient at a wavelength of 360 nm, ε _{400 nm} is the molar extinction coefficient at a wavelength of 400 nm, and ε _{440 nm} is the molar extinction coefficient at a wavelength of 440 nm.)
It is the value obtained more.

2. Method for Producing Titanium-Containing Aqueous Solution The above titanium-containing aqueous solution can be efficiently produced by the method of the present invention described below.
That is, this is a method characterized by adding ammonia and hydrogen peroxide to a titanium raw material to dissolve titanium, and then adding hydroxycarboxylic acid. Specifically, in the presence of ammonia and hydrogen peroxide, titanium hydroxide and / or titanium hydroxide is dissolved in water in the range of pH 7.0 to 14.0, and titanium ions are stabilized with hydroxycarboxylic acid. By doing this, a titanium-containing aqueous solution substantially free of chlorine ions or sulfate ions is obtained.

As a titanium raw material in the method for producing a titanium-containing aqueous solution of the present invention, a titanium hydroxide or a titanium hydrate oxide substantially free of metals other than titanium and anions such as chloride ions and sulfate ions is used.
Here, the titanium hydroxide is a compound represented by a chemical name of orthotitanic acid (TiO ₂ · nH ₂ O, n = 2 or so), and is a generally known method, that is, titanium tetrachloride. Alternatively, an aqueous solution of titanyl sulfate obtained by alkali neutralization and sufficient washing at room temperature to obtain a gel or dried product having a water content of 2.0% by weight or more, more preferably a water content of 5. 0% by weight or more. And those in which anions such as chloride ions, sulfate ions, nitrate ions and the like are substantially not detected are preferably used. The phrase “substantially no anions such as chloride ions are detected” means that the content of anions such as chloride ions or sulfate ions is 5% by weight or less based on TiO ₂ .

On the other hand, titanium hydrated oxide is a compound represented by the chemical name of metatitanic acid (TiO ₂ · nH ₂ O, n = 1 or so), and is used in the sulfuric acid method titanium oxide production process or a substantially equivalent process. A gel-like product obtained by thoroughly washing the solution with water or aqueous ammonia after being hydrolyzed, or dried and having a water content of 2.0% by weight or more, more preferably water content Is 5.0% by weight or more. A sulfate ion content of 5% by weight or less, more preferably 2% by weight or less based on TiO ₂ is preferably used. When the content of sulfate ion in the titanium hydrous oxide is 5% by weight or less, it can be regarded as substantially free of sulfate ion when titanium is supported on the refractory oxide.

The titanium hydroxide and the titanium hydrated oxide may be used in the form of a slurry, but may be dried. Although there is no particular limitation on the drying conditions, the drying conditions are generally selected, that is, under normal pressure or reduced pressure, and at a temperature of 150 ° C. or lower, but are appropriately selected. The TiO ₂ content is determined by weighing after firing at 500 ° C. to remove moisture. The moisture content is indicated by the weight reduction rate measured with a KET moisture meter (maximum temperature 180 ° C.), and the remainder after removing the moisture corresponds to approximately TiO ₂ .
Further, it is generally considered that there is no difference as a chemical species between titanium hydroxide and titanium hydrated oxide, and there is only a difference in the degree of aggregation of the generated fine particles. Needless to say, it's just nothing.

In the present invention, a titanium-containing aqueous solution can be produced according to the following steps.
First, a titanium raw material such as the above titanium hydroxide or titanium hydrated oxide is dispersed in an aqueous medium to form a slurry. At this time, the dispersibility can be improved by making the particles fine using a homogenizer or the like. Subsequently, the slurry containing titanium hydroxide and / or titanium hydroxide is subjected to pH 7.0 to 14.0, preferably pH 8.0 to 13.0 in the presence of an alkali compound, preferably ammonia and hydrogen peroxide. Keep in the range. As a result, most of the titanium raw material is dissolved. The pH is adjusted mainly by the amount of alkali compound added. If the pH is too low, the dissolution of the titanium raw material does not proceed, and if the pH is too high, polymerization of the dissolved titanium ions tends to occur. As the alkali compound, not only ammonia but also a general compound can be used. For example, alkali metal, alkaline earth metal, rare earth metal hydroxide, or the like can be used. In particular, alkali metal hydroxides such as ammonia and sodium hydroxide are preferably used.

The temperature is not particularly limited, but the temperature at which the aqueous solution is usually treated, that is, 5 to 80 ° C., more preferably 10 to 70 ° C. is appropriate. If the temperature is too low, dissolution of the titanium raw material is difficult to proceed. If the temperature is too high, the decomposition reaction of hydrogen peroxide (oxygen release) occurs, and the added hydrogen peroxide is not only wasted, but there is a risk of the dissolution tank rupturing due to an increase in pressure.
As for the addition amounts of ammonia and hydrogen peroxide, ammonia and hydrogen peroxide are added so that ammonia is about 1.5 to 20 mol and hydrogen peroxide is about 1.0 to 20 mol with respect to 1 mol of TiO _2. Add water. If the amount added is too small, the titanium raw material is difficult to dissolve, and even if it is added in excess, the effect of improving the dissolution reaction is not recognized so much.
The order of addition of ammonia and hydrogen peroxide solution is not particularly limited, and it may be added in any way as long as the pH is set within the above range. The general order of addition including the hydroxycarboxylic acid described below is as follows.

(1) ammonia water, hydrogen peroxide water, hydroxycarboxylic acid (2) hydrogen peroxide water, ammonia water, hydroxycarboxylic acid (3) ammonia water / hydrogen peroxide water mixed solution, hydroxycarboxylic acid (4) ammonia water, Ammonia water / hydrogen peroxide mixed solution, hydroxycarboxylic acid (5) Ammonia water, hydroxycarboxylic acid, hydrogen peroxide water After adjusting the pH of the titanium aqueous solution with a small amount of ammonia water, particularly (4) above, A method of adding a solution of hydrogen peroxide in advance and removing heat little by little, adding a hydroxycarboxylic acid after dissolving the titanium raw material, and adjusting the pH by adding ammonia water and hydroxycarboxylic acid of (5), The method of adding hydrogen peroxide little by little to dissolve the titanium raw material is preferred because of the ease of temperature control when dissolving the titanium raw material. It is.

In the process of dissolving the titanium raw material, the decomposition reaction of hydrogen peroxide occurs at the same time, so heat is generated. If the heat removal is not sufficient, there is a risk that the temperature will increase rapidly and the pressure will increase, resulting in an uncontrollable state. Therefore, using a container having a mechanism for adjusting the temperature of the slurry, adjusting the addition rate of aqueous ammonia, hydrogen peroxide and hydroxycarboxylic acid so that the temperature of the slurry falls within the above range, and Injection of dilution water may be necessary to mitigate the temperature rise.
More specifically, the titanium raw material is dissolved by the action of hydrogen peroxide at pH 7 to 14, but hydrogen peroxide itself is easily decomposed even at a low temperature, and the decomposition is further promoted as the temperature rises. Cooling is particularly important when producing on an industrial scale, because if the amount of heat removed is small compared to the amount of heat generated, the temperature of the system may increase and runaway may occur. However, even if the cooling capacity is not sufficient, an increase in the heat capacity of the system can be mitigated by adding an appropriate amount of dilution water, thereby preventing runaway. The dilution water here includes not only water added as water but also water contained in each of the titanium raw material, ammonia water, and hydrogen peroxide. The amount of dilution water added is usually 10 to 100 parts by weight, more preferably 15 to 70 parts by weight, based on 1 part by weight of titanium raw material as TiO ₂ . If the amount of dilution water added is small, the temperature rises due to heat generated by the decomposition of hydrogen peroxide, and there is a risk of runaway. Further, when the amount of dilution water added is large, the concentration decreases, so that it is difficult for the dissolution reaction to occur, and it takes time to concentrate to obtain the target concentration, which is not realistic.

Next, in order to stabilize the titanium-containing aqueous solution obtained by dissolving the titanium raw material in this way, hydroxycarboxylic acid is added. As described above, this hydroxycarboxylic acid may be added to the slurry before the operation of dissolving the titanium raw material, or may be added during or after dissolution.
As this hydroxycarboxylic acid, those having two or more carboxyl groups and one or more hydroxyl groups in one molecule and easily soluble in water are preferable. In particular, the hydroxycarboxylic acid preferably has 12 or less carbon atoms, and more preferably 8 or less carbon atoms. If the carbon number is too large, it is difficult to dissolve in water. On the other hand, if the carbon number is too small, it becomes difficult to contribute to stabilization when the titanium compound is made into an aqueous solution. Specifically, citric acid, malic acid, tartaric acid, lactic acid and the like are preferably used. The addition amount of the hydroxycarboxylic acid to TiO ₂ 1 mol, usually 0.2 to 2.0 moles. If the amount is too small, the stability of the aqueous titanium solution may be impaired. If the amount is too large, it will not only contribute to the stability of the aqueous solution containing titanium, but the viscosity will increase and handling of the impregnating solution will be difficult. The hydroxycarboxylic acid may be added as crystals (grains, powders) or in the form of an aqueous solution. Although the addition temperature of hydroxycarboxylic acid is not specifically limited, Usually, it is performed on the conditions of 50 degrees C or less. More preferably, it is 0 to 40 ° C. or less. A high temperature is not preferred because the residual hydrogen peroxide decomposes rapidly.

After dissolving the titanium raw material and adding the hydroxycarboxylic acid, the residual hydrogen peroxide is removed by maintaining the temperature at a temperature of 10 to 95 ° C. while stirring for 0.5 to 48 hours. In this way, a transparent and stable titanium-containing aqueous solution can be obtained.
The titanium-containing aqueous solution thus prepared is concentrated as an aqueous solution for impregnation with titanium under normal pressure or reduced pressure under conditions similar to the hydrogen peroxide removal step, or diluted at an arbitrary concentration as necessary. be able to. Furthermore, the solid of a titanium containing compound can also be obtained by removing a water | moisture content from titanium containing aqueous solution. The method for removing moisture is not particularly limited, and can be performed by a general method, that is, a drying or freeze-drying method. For example, solids and crystals of a titanium-containing compound can be obtained by drying under normal pressure or reduced pressure for 0.5 to 48 hours under conditions of 50 ° C. or less. Further, it can be pulverized by grinding.

3. Titanium-supported refractory inorganic oxide support Since the titanium-containing aqueous solution prepared by the method of the present invention is stable in a wide pH range (2 to 12), titanium is uniformly supported on the refractory inorganic oxide in a highly dispersed manner. can do. In addition, the titanium-containing aqueous solution is safe because it does not contain any substances that are difficult to remove even when baked, such as metals other than titanium, chlorine ions, and sulfate ions, and that may adversely affect the surface state of the catalyst. It is surely applicable to industrial uses. In addition, by supporting titanium in a highly dispersed manner in a refractory inorganic oxide, the interaction between titanium and the active metal is strengthened, so that a highly active state of the active metal can be formed with a small amount of titanium, and the cost is low. A simple catalyst can be produced.

Next, the manufacturing method of the titanium carrying | support refractory inorganic oxide support | carrier of this invention is demonstrated.
In this method, a titanium-supported refractory inorganic oxide support is produced by bringing the titanium-containing aqueous solution obtained as described above into contact with a refractory inorganic oxide support.
The refractory inorganic oxide carrier used in this method is not particularly limited as long as it is an inorganic oxide having an OH group on the surface, but for the purpose of the present invention, alumina, silica, silica-alumina, magnesia is used. Zinc oxide, crystalline aluminosilicate, clay mineral, calcium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, silver oxide, tin oxide, bismuth oxide and mixtures thereof Preferably used. Among these, alumina, particularly γ-alumina is preferable. The average pore diameter is preferably in the range of 5 to 15 nm. Although it does not specifically limit about a shape, Molded objects, such as a powder, a cylinder, a three-leaf, a four-leaf, are used suitably.

  The method for bringing the titanium-containing aqueous solution into contact with these refractory inorganic oxide carriers and supporting the titanium on the carrier is not particularly limited, and the titanium-containing aqueous solution is adjusted to an amount that the carrier absorbs water. It can be carried out under ordinary pressure or reduced pressure by a general method such as impregnation and pore filling method (impregnation method) or a method of immersing the carrier in a large excess of titanium aqueous solution. The titanium-containing aqueous solution prepared by the method of the present invention is stable in the range of pH 2 to 12, and the pH can be adjusted with ammonia water or organic acid. In general, in consideration of the state of the surface hydroxyl group, for example, when supported on alumina, it is preferable to support at pH 5-7, and when supported on silica, supported at about pH 3-5.

The amount of titanium supported is preferably 0.5 to 30% by weight, more preferably 1 to 15% by weight based on the oxide (TiO ₂ ) based on the refractory inorganic oxide carrier. If the loading amount is too small, the effect of adding the metal may not be sufficiently exhibited.If the loading amount is too large, uneven deposition or aggregation may occur on the support, and a sufficient effect cannot be obtained. It is not preferable.
After bringing the titanium-containing aqueous solution into contact with the carrier, a titanium-carrying carrier can be obtained by treating with a general method such as drying and baking. The drying is usually performed at normal pressure or reduced pressure, preferably at a temperature of 50 to 300 ° C., more preferably 100 to 120 ° C., for about 0.5 to 100 hours. Further, in order to enhance the binding property to the carrier, firing is performed as necessary. The firing temperature is preferably 300 to 650 ° C., more preferably 450 to 600 ° C., and the firing time is usually about 0.5 to 100 hours.

4). Hydrocarbon oil hydrotreating catalyst The hydrocarbon oil hydrotreating catalyst of the present invention is obtained by adding the titanium-supported refractory inorganic oxide support obtained in the above manner to Groups 6 and 8 of the periodic table. It can be prepared by supporting at least one metal selected from metals belonging to Group 9 and Group 10.
As the active metal species of this catalyst, molybdenum, tungsten or the like is used as the Group 6 metal of the periodic table, but molybdenum is particularly preferably used. As the molybdenum compound, molybdenum trioxide, ammonium paramolybdate and the like are suitable. As the tungsten compound, tungsten trioxide, ammonium tungstate and the like are suitable. The supported amount (oxide basis) is preferably 4 to 40% by weight, more preferably 8 to 35% by weight, based on the total amount of the catalyst.
As the Group 8-10 metal, usually cobalt or nickel is preferably used. As the cobalt compound, cobalt carbonate and cobalt nitrate are preferable, and as the nickel compound, nickel carbonate and nickel nitrate are preferable. The supported amount (oxide basis) is preferably 1 to 12% by weight, more preferably 2 to 10% by weight, based on the total amount of the catalyst.
Furthermore, it can trigger carrying a phosphorus compound, as the phosphorus compound, phosphorus pentoxide, etc. orthophosphoric acid are used. The supported amount (oxide basis) is preferably 0.5 to 8% by weight, more preferably 1 to 6% by weight, based on the total amount of the catalyst.

The active metal compound is usually supported by an impregnation method. The Group 6 and Group 8-10 metals and the phosphorus compound may be impregnated separately, but it is efficient to do so simultaneously. Preferably, the metal compound is 0.7 to 7.0 mol / liter for Group 6 metal, 0.3 to 3.6 mol / liter for Group 8 to 10 metal, and 0 to 2.2 for phosphorus compound. It is preferable to dissolve in pure water at a ratio of mol / liter and impregnate the titanium-supported carrier after adjustment so as to be equivalent to the water absorption rate. In consideration of the stability of the impregnating solution, the pH at the time of impregnation is generally 1 to 4, preferably 1.5 to 3.5 in the acidic region, and 9 to 12, preferably 10 to 11 in the alkaline region. The pH can be adjusted using an organic acid or ammonia.
In particular, it is preferable to add a water-soluble organic compound such as polyethylene glycol having a molecular weight of 90 to 10,000 to the impregnating solution stabilized with a phosphorus compound. The amount added is preferably 2 to 20% by weight, more preferably 3 to 15% by weight, based on the carrier.
After the impregnation, a normal heat treatment is performed. In the case where the impregnation is performed sequentially, any method in which heat treatment is performed each time impregnation or not is used. It is advantageous to perform the heat treatment in air usually at 550 ° C. or lower for about 3 to 16 hours. The catalyst of the present invention thus prepared is used as a hydrotreating catalyst for hydrocarbon oil.

5. Production method of hydrocarbon oil As the hydrocarbon oil to be treated using the above catalyst, all petroleum fractions can be used. Specifically, kerosene, light diesel oil, heavy diesel oil, cracked diesel oil, etc. are used for normal pressure. Residual oil, vacuum residual oil, dewaxed vacuum residual oil, asphaltene oil, tar sand oil and the like can be mentioned. The catalyst of the present invention is particularly useful as a hydrotreating catalyst for an ultra deep desorption region (a sulfur content of 50 ppm or less) of a light gas oil fraction. Specifically, the hydrotreating catalyst described above is obtained by hydrotreating a hydrocarbon oil having a boiling point of 140 to 400 ° C., so that the sulfur content is 50 wtppm or less, preferably 30 wtppm or less, more preferably 20 wtppm or less, It is preferably used for producing a hydrocarbon oil of 10 wtppm or less.
The conditions for hydrotreating such a fraction are the same as those for normal hydrotreating. For example, the reaction temperature is 250 to 400 ° C., the reaction pressure is 2 to 10 MPa, and the hydrogen / feed oil ratio is 50 to 500 Nm ³ / kg. Liter, liquid hourly space velocity (LHSV) 0.2-5.0 hr ⁻¹ .

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

<Preparation example of titanium compound>
Reference Example 12.7 g of titanium hydrous oxide powder having a titanium oxide (TiO ₂ ) ratio of 85 wt% obtained by baking at 500 ° C. for 4 hours and 70 g of pure water are placed in a 1 L glass beaker. And stirred to make a slurry. Next, an aqueous solution in which 78.7 g of 35 wt% aqueous hydrogen peroxide and 26.5 g of 26 wt% aqueous ammonia were mixed was added to the hydrous titanium oxide slurry. Then, it stirred for 3 hours, maintaining 25 degreeC, and obtained the yellow-green and transparent titanium containing aqueous solution. There, 28.4 g of citric acid monohydrate was added. Then, after hold | maintaining for 6 hours at the temperature of 30 degrees C or less, 120 g of transparent titanium containing aqueous solution by pH 6.2 was obtained by hold | maintaining at 80-95 degreeC for 12 hours. Furthermore, this compound was dried under reduced pressure for 2 hours at 30 ° C. to obtain a powder.
Elemental analysis of this powder gave the following elemental analysis values (excluding moisture).
C (24.2 wt%), H (4.1 wt%), N (10.0 wt%), O (45.4 wt%), Ti (16.3 wt%)
In addition, the presence of ammonium, COO-, and Ti = O was confirmed by IR spectroscopy. Together with the results of elemental analysis, it was found that 2 equivalents of ammonium group and 1 equivalent of citrate group existed per 1 equivalent of Ti. It was. As a result, this powder was estimated to be (NH ₄ ) ₂ [Ti (O) (citrate group)].

In addition, said analysis was performed using the following apparatus.
C, H, N: Measured using a commercially available CHN analyzer (combustion-TCD method).
O: Measured using a commercially available oxygen analyzer (high temperature extraction-infrared method).
Ti: Measured using a commercially available ICP apparatus (emission spectroscopic analysis).
IR spectroscopic analysis was measured using a commercially available FT-IR apparatus.
Since the sample contained water such as crystal water, the elemental analysis of each sample with different drying conditions was performed, the results were examined in detail, and the chemical formula was determined.
When the residual hydrogen peroxide concentration of the titanium-containing aqueous solution was measured by the oxidation-reduction titration method (potassium iodide method), the residual hydrogen peroxide amount was 0.03 mol with respect to 1 mol of Ti. Further, when the anion concentration of the impurity was measured using a commercially available anion chromatograph, the impurity (mainly SO ₄ ) was 1.9 wt% with respect to TiO ₂ .

Reference Example 12.7 g of titanium hydrous oxide powder having a titanium oxide (TiO ₂ ) ratio of 85 wt% obtained by baking at 500 ° C. for 4 hours and 70 g of pure water are placed in a 1 L glass beaker. And stirred to make a slurry. Next, 11.3 g of caustic soda having a purity of 96 wt% was added. Next, 78.7 g of 35 wt% aqueous hydrogen peroxide was added to the hydrous titanium oxide slurry. Then, it stirred for 3 hours, maintaining 25 degreeC, and obtained the yellow-green and transparent titanium containing aqueous solution. There, 28.4 g of citric acid monohydrate was added. Then, after hold | maintaining for 6 hours at the temperature of 30 degrees C or less, 120 g of transparent titanium containing aqueous solution by pH 6.2 was obtained by hold | maintaining at 80-95 degreeC for 12 hours. Furthermore, this compound was dried under reduced pressure at 30 ° C. to obtain a powder.
The powder was analyzed in the same manner as in Example 1.
The results are as follows.
Elemental analysis values (excluding moisture):
C (24.5 wt%), H (1.4 wt%), N (15.4 wt%), O (42.6 wt%), Ti (16.1 wt%)

The presence of COO- and Ti = O was also confirmed by IR spectroscopy, and together with the elemental analysis results, it was found that 2 equivalents of sodium and 1 equivalent of citric acid group existed per 1 equivalent of Ti. As a result, this powder was estimated to be (Na) ₂ [Ti (O) (citrate group)].
In addition, when the residual hydrogen peroxide concentration of the titanium-containing water and solution was measured by the oxidation-reduction titration method (potassium iodide method), the residual hydrogen peroxide amount was less than 0.01 with respect to 1 mol of Ti and was not detected. . Further, when the anion concentration of the impurity was measured using a commercially available anion chromatograph, the impurity (mainly SO ₄ ) was 1.9 wt% with respect to TiO ₂ .

<Titanium-containing aqueous solution preparation example>
Example 3
500 g of titanium tetrachloride and 1 liter of pure water were cooled with ice. Pure water was stirred, and titanium tetrachloride was gradually added dropwise while cooling to obtain a colorless titania sol hydrochloric acid solution. To this titania sol solution, 1.2 times equivalent of ammonia water (concentration: 1 mol / liter) was added dropwise and stirred for 1 hour to obtain a titanium hydroxide gel. The titanium hydroxide gel was separated by suction filtration, redispersed in about 1 liter of pure water, and washed by filtration. This operation was repeated 4 to 5 times until the washing solution became neutral, and it was confirmed that silver nitrate was free of chloride ions. 134.3 g of the resulting titanium hydroxide gel (water content 80.4% by weight) was collected and stirred, and 43 ml of 25% by weight ammonia water was added to adjust the pH to 11.5. Next, 76 ml of 30 wt% hydrogen peroxide water was gradually added so that the temperature of the titanium hydroxide gel aqueous solution did not exceed 40 ° C., and the titanium hydroxide gel was dissolved to obtain a yellow-green transparent titanium-containing aqueous solution. . The pH of the titanium-containing aqueous solution at the dissolution step was 9.7 at the minimum. Thereto, 27.1 g of citric acid monohydrate was gradually added so that the temperature of the titanium-containing aqueous solution did not exceed 40 ° C. Thereafter, the temperature of the titanium-containing aqueous solution was kept at 40 ° C. for 30 minutes, 50 ° C. for 30 minutes, and 80 ° C. for 6 hours to obtain 250 ml of a transparent titanium-containing aqueous solution (A1) at pH 6.2.
The UV-VIS spectrum of this titanium-containing aqueous solution (A1) is shown in FIG. As shown in FIG. 1, the titanium-containing aqueous solution (A1) had a strong absorption spectrum in the ultraviolet region, and was stable over a wide range of pH 2 to 13 for a long time.

Example 4
To 25.8 g of hydrous titanium oxide powder having a water content of 16.5% by weight, 135 ml of pure water was added and slurried and stirred. Next, 20 ml of 25 wt% aqueous ammonia was added to adjust the pH to 11.7. Further, 81 ml of 25 wt% ammonia water and 141 ml of 30 wt% hydrogen peroxide water were mixed and cooled to room temperature, and gradually added so that the temperature of the slurry did not exceed 40 ° C. A titanium-containing aqueous solution was obtained. Thereto, 56.7 g of citric acid monohydrate was gradually added so that the temperature of the titanium-containing aqueous solution did not exceed 40 ° C. Then, after holding at 40 ° C. for 30 minutes, 50 ° C. for 30 minutes, and 60 ° C. for 30 minutes, holding at 80 ° C. for 6 hours gave 99 ml (A2) of a transparent titanium-containing aqueous solution at pH 6.0. .
The UV-VIS spectrum of this titanium-containing aqueous solution (A2) is shown in FIG. As shown in FIG. 2, the titanium-containing aqueous solution (A2) had a strong absorption spectrum in the ultraviolet region, and was stable over a wide range of pH 2 to 13 for a long time.

Example 5
To 23.9 g of hydrous titanium oxide powder having a water content of 9.8% by weight, 122 ml of 25% by weight ammonia water was added and slurried. When 17.0 g of citric acid monohydrate was added little by little so that the temperature of the slurry did not exceed 40 ° C., the pH became 10.4. Next, 169 ml of 30% by weight hydrogen peroxide water was gradually added so that the temperature of the slurry did not exceed 40 ° C. After completion of the addition of hydrogen peroxide, the mixture was kept at 30 ° C. for 1 hour to obtain a yellow and transparent titanium-containing aqueous solution. Then, after maintaining at 40 ° C. for 30 minutes and at 50 ° C. for 2 hours, by maintaining at 80 ° C. for 6 hours, 90 ml (A3) of a yellow transparent titanium-containing aqueous solution having a pH of 6.2 was obtained.
The UV-VIS spectrum of this titanium-containing aqueous solution (A3) is shown in FIG. As shown in FIG. 3, the titanium-containing aqueous solution (A3) had a strong absorption spectrum in the ultraviolet region, and was stable over a wide range of pH 2 to 13 for a long time.

Comparative Example 1
To 25.8 g of hydrous titanium oxide powder having a water content of 16.5% by weight, 135 ml of pure water was added and slurried and stirred. Next, when 20 ml of 25 wt% aqueous ammonia was added to the slurry, the pH was 11.2. Next, when 141 ml of 30 wt% hydrogen peroxide water was gradually added so that the temperature of the slurry did not exceed 40 ° C., the pH gradually dropped from 11.2, and before the hydrous titanium oxide was dissolved, 6. It became 9 or less. Thereafter, the mixture was kept at 40 ° C. for 2 hours, but the dissolution of hydrous titanium oxide did not proceed. Therefore, 56.7 g of citric acid was added and kept at 40 ° C. for 30 minutes, 50 ° C. for 2 hours, and 80 ° C. for 6 hours. There was much undissolved residue, and a transparent titanium-containing aqueous solution could not be obtained.

Comparative Example 2
To 23.9 g of hydrous titanium oxide powder having a water content of 9.8% by weight, 135 ml of pure water was added and slurried and stirred. When 17.0 g of citric acid monohydrate was added and then 20 ml of 25 wt% aqueous ammonia was added, the pH was 8.6. Next, when 169 ml of 30 wt% hydrogen peroxide water was gradually added so that the temperature of the slurry did not exceed 40 ° C., the pH gradually decreased from 8.6, and before the hydrous titanium oxide was dissolved, Reduced to .5. Thereafter, it was held at 35 ° C. and 40 ° C. for 2 hours, respectively. However, since it did not dissolve, it was further held at 80 ° C. for 6 hours.

Comparative Example 3
To 23.9 g of hydrous titanium oxide powder having a water content of 9.8% by weight, 135 ml of pure water was added and slurried and stirred. When 79.5 g of citric acid monohydrate was added and then 84 ml of 25 wt% aqueous ammonia was added, the pH was 5.8. Next, when 30 ml of hydrogen peroxide solution (141 ml) was gradually added so that the temperature of the slurry did not exceed 40 ° C., the pH gradually decreased from 5.8 to pH 5.5. Thereafter, it was kept at 35 ° C., 40 ° C., and 50 ° C. for 2 hours each and further at 80 ° C. for 6 hours, but a transparent titanium-containing aqueous solution was not obtained.

Comparative Example 4
When 52.9 g of a 30 wt% titanium sulfate aqueous solution was diluted to 80 ml with pure water, a colorless and transparent aqueous solution (A4) having a pH <1 was obtained. When the pH was adjusted using aqueous ammonia, gelation occurred around pH 1, so that the aqueous solution (A4) itself was used as the impregnation solution.
The UV-VIS spectrum of this aqueous titanium sulfate solution (A4) is shown in FIG. As shown in FIG. 4, the titanium sulfate aqueous solution (A4) has a very strong absorption spectrum in the ultraviolet region.
As described above, the preparation methods of the titanium-containing aqueous solutions and the molar extinction coefficient ε (UV-VIS spectrum) of the titanium-containing aqueous solutions in Examples 3 to 5 and Comparative Examples 1 to 4 are collectively shown in Tables 1 and 2, respectively. .

Reference Example 16.0 kg of hydrous titanium oxide powder having a titanium oxide (TiO ₂ ) ratio of 85 wt% determined by firing at 500 ° C. for 4 hours, 320 kg of pure water, and 33.5 kg of 26 wt% ammonia water. The reactor was charged into a reactor having an internal volume of 0.5 m ³ , stirred, slurried and cooled. Next, 99.2 kg of 35 wt% hydrogen peroxide water was added little by little over 1 hour so that the temperature of the hydrous titanium oxide slurry was maintained at 20 ° C. Thereafter, the mixture was stirred for 3 hours while maintaining 20 ° C. to obtain a yellow-green transparent titanium-containing aqueous solution. Thereto, 35.8 kg of citric acid monohydrate was gradually added so that the temperature of the titanium-containing aqueous solution did not exceed 25 ° C. Then, after hold | maintaining for 4 hours at the temperature of 30 degrees C or less, 180 kg (A5) of transparent titanium containing aqueous solution by pH 6.2 was obtained by hold | maintaining at 80-95 degreeC for 12 hours. The weight ratio of dilution water / TiO ₂ was 30.3.

Comparative Example 5
13.0 kg of hydrous titanium oxide powder having a titanium oxide (TiO ₂ ) ratio of 85 wt% determined by firing at 500 ° C. for 4 hours, 33.5 kg of 26 wt% ammonia water and 26 wt% ammonia water. The reactor was charged into a reactor having an internal volume of 0.5 m ³ , stirred, slurried and cooled. Next, when 99.2 kg of a 35 wt% aqueous hydrogen peroxide solution was added little by little to the hydrous titanium oxide slurry, the temperature of the aqueous solution could not be maintained at 20 ° C. despite the maximum cooling capacity. Increased, the addition rate of the mixed aqueous solution was decreased. After the addition of the mixed aqueous solution was completed over 6 hours, the temperature was kept at 20 ° C., and the dissolution of the hydrous titanium oxide was waited. As a result, the temperature of the slurry gradually increased, decomposition of hydrogen peroxide began, and the internal pressure slightly decreased. Since it began to rise gradually, the liquid was removed to stop the reaction. As a result of this abnormal phenomenon, a transparent titanium-containing aqueous solution was not obtained. The weight ratio of dilution water / TiO ₂ was 7.9.

<Example of carrier preparation>
Example 7
50 ml of the titanium-containing aqueous solution (A1) was diluted with pure water to 80 ml, and impregnated under a normal pressure into 100 g of cylindrical γ-alumina with a pore volume of 0.8 ml / g (pore filling method). Then, after drying at 70 ° C. for 1 hour under vacuum, it was dried at 120 ° C. for 3 hours, and finally calcined at 500 ° C. for 4 hours to obtain a titania 5 wt% supported alumina carrier (B1). The obtained titania-carrying alumina carrier B1 (molded body) was subjected to EPMA analysis in the diameter direction. FIG. 5 shows the analysis result of this EPMA. As can be seen from FIG. 5, the titania-carrying alumina carrier (B1) carries titania uniformly from the outside to the inside.

Example 8
Titanium-containing aqueous solution (A2) 24 ml was diluted with pure water to 80 ml, and impregnated under a reduced pressure (pore filling method) into 100 g of cylindrical γ-alumina with a pore volume of 0.8 ml / g. Then, after drying at 70 ° C. for 1 hour under vacuum, it was dried at 12 ° C. for 3 hours and finally calcined at 500 ° C. for 4 hours to obtain a titania 5 wt% supported alumina carrier (B2). The EPMA analysis of the diameter direction of the obtained titania carrying | support alumina support | carrier (B2) (molded object) was performed.
FIG. 6 shows the results of this EPMA analysis. As can be seen from FIG. 6, the titania-carrying alumina carrier (B2) carries titania uniformly from the outside to the inside.

Example 9
A titanium-containing aqueous solution (A3) (47 ml) was diluted with pure water to 80 ml, and impregnated with 100 g of cylindrical γ-alumina with a pore volume of 0.8 ml / g under reduced pressure (pore filling method). Then, after drying at 70 ° C. for 1 hour under vacuum, it was dried at 120 ° C. for 3 hours, and finally calcined at 500 ° C. for 4 hours to obtain a titania 5 wt% supported alumina carrier (B3). EPMA analysis in the diameter direction of the obtained titania-supported alumina support (B3) (molded product) was performed.
FIG. 7 shows the results of this EPMA analysis. As can be seen from FIG. 7, the titania-carrying alumina carrier (B3) carries titania uniformly from the outside to the inside.

Comparative Example 6
52.9 g of a 30% by weight aqueous solution of titanium sulfate was diluted with pure water to 80 ml, and impregnated with 100 g of cylindrical γ-alumina with a pore volume of 0.8 ml / g under reduced pressure (pore filling method). Then, after drying at 70 ° C. for 1 hour under vacuum, it was dried at 120 ° C. for 3 hours and finally calcined at 500 ° C. for 4 hours to obtain a titania 5 wt% supported alumina carrier (B4). The obtained titania-carrying alumina support (molded body) was subjected to EPMA analysis in the diameter direction.
FIG. 8 shows the EPMA analysis results. As can be seen from FIG. 8, titania-carrying alumina carrier (B4) is unevenly distributed with titania.
The compositions of the carriers prepared in Examples 7 to 9 and Comparative Example 6 are collectively shown in Table 3.

<Catalyst preparation example>
Example 10
250 ml of pure water was added to 69.5 g of nickel carbonate (39.7 g as NiO), 220 g of molybdenum trioxide, 31.5 g of orthophosphoric acid (purity 85%: 19.5 g as P ₂ O ₅ ), and the mixture was stirred with 80 ml. After dissolving at ° C. and cooling at room temperature, the volume was adjusted to 250 ml with pure water to prepare an impregnating solution (S1).
50 ml of impregnating solution S1 was collected, 6 g of polyethylene glycol (molecular weight 400) was added, diluted and fixed in pure water to meet the water absorption of 100 g of carrier (B2), impregnated at normal pressure, After vacuum drying at 70 ° C. for 1 hour, heat treatment was performed at 120 ° C. for 16 hours to prepare Catalyst C1.

Comparative Example 7
50 ml of the impregnating solution S1 was collected, 6 g of polyethylene glycol (molecular weight 400) was added, diluted and constant volume with pure water to meet the water absorption of 100 g of the carrier (B4), impregnated at normal pressure, After drying in vacuo at 70 ° C. for 1 hour, heat treatment was performed at 120 ° C. for 16 hours to prepare Catalyst C2. Table 4 shows the compositions of the catalysts prepared in Example 10 and Comparative Example 7.

<Hydrodesulfurization treatment of light oil>
Example 11
100 ml of catalysts C1 and C2 were filled in a fixed bed flow type reaction tube, respectively. The feedstock oil was circulated in an up-flow format introduced from the bottom of the reaction tube together with hydrogen gas, and the reactivity was evaluated.
As a pretreatment, a raw material oil “Middle East straight run diesel oil (LGO)” having the properties shown in Table 5 was circulated together with hydrogen gas and presulfided. After the preliminary sulfidation, the hydrodesulfurization reaction was carried out by circulating the above-mentioned raw material oil “Middle Eastern straight gas oil (LGO)” together with hydrogen gas. The reaction temperature was 320 ° C. to 350 ° C., hydrogen partial pressure 5 MPa, hydrogen / feed oil ratio 250 Nm ³ / kiloliter, and LHSV = 2.0 hr ⁻¹ .
Using the average value of the desulfurization rate constant evaluated at 320 to 350 ° C., when the relative desulfurization activity was determined with the average value of the desulfurization rate constant of Comparative Example 7 (Catalyst C2) as 100, Example 10 (Catalyst C1) was 135.

According to the present invention, it is stable in a wide pH range, substantially free of metals other than titanium, chlorine ions, and sulfate ions, so that titanium is uniformly supported on a refractory inorganic oxide support. A suitable titanium-containing aqueous solution can be produced easily and inexpensively.
By using this titanium-containing aqueous solution, it is possible to provide a refractory inorganic oxide carrier supporting titanium in a highly dispersed state, and a highly active and low-cost hydrocarbon oil hydrotreating catalyst. Further, by using such a catalyst, it is possible to efficiently produce a hydrocarbon oil having a low sulfur content.

4 is a UV-VIS spectrum diagram of the aqueous titanium-containing solution obtained in Example 3. FIG. 4 is a UV-VIS spectrum diagram of the aqueous titanium-containing solution obtained in Example 4. FIG. 6 is a UV-VIS spectrum diagram of the aqueous titanium-containing solution obtained in Example 5. FIG. 5 is a UV-VIS spectrum diagram of the aqueous titanium sulfate solution obtained in Comparative Example 4. FIG. 6 is a chart showing EPMA analysis results of a titania-supported alumina carrier obtained in Example 7. 6 is a chart showing EPMA analysis results of a titania-supported alumina carrier obtained in Example 8. 10 is a chart showing EPMA analysis results of a titania-supported alumina carrier obtained in Example 9. 7 is a chart showing EPMA analysis results of a titania-supported alumina carrier obtained in Comparative Example 6.

Claims (2)

In the presence of ammonia and hydrogen peroxide, in the range of pH 7.0 to 14.0, titanium hydroxide and / or titanium hydroxide is dissolved in water, and titanium ions are stabilized with hydroxycarboxylic acid. characterized method of anion content of chlorine ion or sulfate ion is more than 5% by weight of the titanium-containing aqueous solution with TiO ₂ basis.   A method for producing a titanium-supported refractory inorganic oxide support, comprising bringing the titanium-containing aqueous solution obtained by the method according to claim 1 into contact with a refractory inorganic oxide support.

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